Amazon EC2 Auto Scaling group Availability Zone distribution
The following information describes Amazon EC2 Auto Scaling group Availability Zone strategies.
- Balanced best effort
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Amazon EC2 Auto Scaling maintains an equal number of instances across enabled Availability Zones. If launch attempts fail in an Availability Zone, Amazon EC2 Auto Scaling attempts to launch instances in another healthy Availability Zone. This strategy is important for applications that need Availability Zone redundancy and are not impacted by imbalanced groups.
- Balanced only
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Amazon EC2 Auto Scaling maintains an equal number of instances across enabled Availability Zones. If launch attempts fail in an Availability Zone, Amazon EC2 Auto Scaling will continue to attempt to launch instances in the Availability Zone. This strategy is important to meet certain requirements such as quorum-based workloads or if your Amazon EC2 Auto Scaling group can tolerate the loss of an Availability Zone because you have sufficient capacity in the remaining Availability Zones.
The Availability Zone distribution strategy selection is in the Network section of the AWS Management Console or
you can use the create-auto-scaling-group
For more information, see Create Amazon EC2 Auto Scaling groups using launch templates.
